I for some reason can't vote on this, but I felt like saying that the wire hanging from the ceiling would be a giveaway that you didn't actually rip off your head, but you could set it up that after an initial force acted on the wire and it no longer had any resistance (you decapitate yourself) the wire gets pulled up into the ceiling, so that they'd just see you holding your decapitated head in your hands and a stool sitting next to you.

no, the best way is to tie rope to all of your body parts individually and to tie that cutting wire to each of your joints, the ropes for each being longer than the cutting wire. When you end up, you should be a human windchime hanging from a bridge.

everyone knows the kewlest way to kill yourself is to strap pork chops to yourself along with a helmet-cam and hang around large hungry carnivorous creatures
like bears or sharks
or maybe put on a helmet-cam and wrap yourself in tinfoil and skydive into a thunderhead

When I develop lung cancer and have a damaged liver at the age of 39 I'm going to get "Your job sucks" tattooed on my *ss then go sky diving naked without a parachute and do my best to land on a sidewalk or road. Just as one final joke to the person that has to clean me up.